Heating apparatus.



No. 795,464. PATENTBD JULY 25, 1905.

' W. S.l WASHBURN. A

'HEATING APPARATUS.

APPLIOATION :man AUG. 26.1904.

2 SHEETS-SHEET 1.

PATENTED JULY 25. 1905.

W. S. WASHBURN. HEATING APPARATUS. APPLICATION PILE1V AUG.26.1904.

2 SHEETS-SHEET 2.

'Illlll'lx IIIIIIIIIIIII IIIIIIIIIIIIIIII UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented July 25, 1905.

Application led August 26, 1904. Serial No. 222,257.

To n/ZZ 1071/077?, it may concern.-

Beit known, that I, WILLIAM S. WASHBURN, of Brockton, in the county ofPlymouth and State of Massachusetts, have invented certain new anduseful Improvements in Heating Apparatus, of which the following' is aspecilication.

This invention relates to heatingappliances, and particularly to thatclass of appliances used to generate steam or to heat, water to supplythe heating' systems of buildings; and its object is to produce a Waterheater or boiler which will deliver hot water or steam from a pointdirectly over the hottest part of the lire and which will utilize theheat remaining in the waste products of combustion for heating thereturn water before the latter passes into the steam-chamber or mainheating portion of the boiler or heater.

In all types of boilers and furnaces now used for heating purposes thesteam or hot water is taken from the part of the heater farthest removedfrom the source of heat and therefore the coolest part, and thereturning' cool water is fed into the hottest portion of the heater,with the result that in the case of a steam-generator the greater partof the heat given off by the fire is used up in bringingthe cool waterto the boiling-point, while the steam in the upper part of thegeneratingchamber, being acted on only by the products of combustionwhich have lost most of their heat, is delivered at a comparatively lowtemperature, ready to be quickly condensed in the pipes and radiatorsand immediately return to increase the burden put on the boiler, whilethe Water in the steam-chamber is unnecessarily chilled, and in the caseof a hotwater heater water at a temperature less than the maximum isdelivered to the heating system with resulting' loss of efficiency,Whereas in my improved apparatus the water is fed into chambers abovethe steam-chamber or main heating portion into contact with the coolergases, and is then, after being heated thereby, caused to pass into achamber directly over the fire-box, where it is quickly evaporated orheated in the case of a hot- Water heater.

By the construction and arrangement of the parts of my improvedapparatus less of the heat of the lire is Wasted, and steam is generatedor water heated more quickly and delivered at a higher temperature, withless expenditure of fuel, than is the case with any of the contrivanceshitherto known.

In the drawings forming a part of this specification, Figure l is avertical central section of a steam-boiler embodying the preferred formof my invention. Fig. 2 is a hori- Zonta] cross-section on line2 2 ofFig. 1. Fig. 3 is a vertical section of a modified form of my invention,showing one of the parts of a sectional boiler. Fig. A is across-section on the linea 4 of Fig. 3. Fig. 5 is a view similar to Fig.l, showing my invention applied to a hot-water heater.

, The same reference characters indicate the same parts in all thefigures.

The boiler constituting the preferred form of my invention isconstructed with a chamber a, into which water is fed and in which steamis generated. The chamber a therefore constitutes a steam-generatingchamber or steam-dome,or, more broadly, a main heatingchamber. Directlybeneath the steam-generating chamber is a fire-box t, at the bottom ofwhich is placed a grate g, and beneath the latter is the ash-pit p.

The side walls w of the fire-box are preferably formed double, with aspace e between them opening into the chamber a, constituting awater-leg, by virtue of which the water in the boiler is caused tosurround the fire, and thereby receive the greatest possible proportionof the heat given off by the fire. The upper portion of the fire-box ispreferably enlarged and the crown-sheet s of greater area than thegrate-surface, a construction Which increases the heating-surface andallows the hot products of combustion to expand and more efficientlycommunicate heat to the water in the steam-generating chamber. A numberof iiues f extend through the chamber @,opening at their ends into thefire-box and into passages hereinafter described, leading to an outletto the chimney,through which the products of combustion pass. An outleto is formed in the upper part of the steam-chamber a, through which thesteam passes to the pipes and radiators of the heating system.

Above the steam-chamber is a water-chamber l, having an inlet (Z,through which the water formed by condensation of the steam in theheating-pipes is caused to flow into the chamber, and above the chamberl is a second water-chamber 2. The chambers l and2 constitute together awater-receiving portion. In the form of my invention shown in Fig. l thewater-chambers are made of short cylindrical boxes provided with ues 7c,extending through them from top to bottom and SO mounted that anair-tight space l is provided between them and a similar space m betweenthe lower water-chamber l and thc steamchamber (L. Openings are formedin the top of the chamber l and the bottom of the chamber 2 and arejoined by a water-tight connection,forming a passage r, through whichwater may pass freely. A pipe A leads from the upper part of the upperwater-chamber downward into a pipe B, which is connected to the top ofthe steam-generating chamber c and extends to the lower part thereof,its lower end being normally submerged in the water of thesteam-chamber. 1f desired, the pipe B may be omitted and thepipcAallowed to discharge directly into the steam-generating chamber.

rlhe products of combustion pass upward through the iiues f, 72., andand spaces fm, and l to a smoke-box t, from which they are dischargedthrough a pipe into the chimney. The water formed by condensation ofsteam in the heating-pipes flows through the inlet Z into thewater-chamber l, wherein it circulates and is heated by thehot smoke andgases passing about and through the said chamber, thence through thepassage fr into the upper water-chamber 2, where it is further heated ina similar manner, and finally through the pipes A and B into thesteamgenerating chamber.

The precise form andarrangcmentoffparts shown are not essential to myinvention, the essential features being the location of the generator ormain heating-chamber near the hottest part of the fire and of thereturn-water chambers in a position to be acted on by the gases whichhave already expended a part of their heat in generating and heating thesteam; nor is the precise number of waterchambers shown essential, 4asany number arranged in any desired fashion which may be necessary toabsorb most effectively the greatest possible amount of heat from thewaste gases may be used.

Minor changes may be made in the structure illustrated, as by taking thesteam for the heating system from above the pipe A or leading' avent-pipe from over the pipe A to the steam-main, if desired, withoutaffecting the invention. lf desired,ribs may be formed in thecrown-sheet s for increasing its effective heatingsurface.

In Fig. l I show a pipe t, which communicates with the dome a above thepipe A. Said pipe may extend to the supply end of the heating system forthe purpose of liberating any steam or air that may collect in thepreliminary heating portion.

The modification shown in Figs. 3 and 4 illustrates a form of myinvention in which the boiler is formed of a number of thin fiatvertical sections connected together, one of such sections being hereshown. The section is formed with two legs, between which is left aspace 71, which with similar spaces formed in the other sections withwhich it is used forms the fire-box. In the central part of' the sectionis the steam-generating chamber ft, and in the upper part of the sectionis the return-water chamber 3. Openings Z m extend through the chamber 3from side to side of the section, and through these openings theproducts of combustion pass on their way to the chimney. The water ofcondensation is let into the chamber 3 by the inlet d and circulatesabout this chamber, overflowing the inner wall y thereof into thepassage A. l and so down into the generating-chamber c. The steam ormain heating chamber a is separated from the return-water chamber 3 by awall w, which may be a single wall, but is preferably formed double,with a space 0 between the portions of the wall, which space maybefilled with some suitable non-conducting material or with air for thepurpose of insulating' the chamber a from the chamber 3 and preventingloss of heat from the steam in the heating-chamber by conduction to thecool water in the return-water chamber. The steam generated in thechamber c' flows through the outlet n, which leads to the steam-main.The sections arc placed closely together side by side and connected insuch manner that the steam-outlet c of each of them communicates withthe outlets of all. There are also passages at c and at the bottom ofthe water-legs of the chambers c and 3, respectively, connecting all thesections through which water is free to flow to maintain the water-leveluniform in all the sections of the boiler. The products of combustionpass through the fire-box to the rear of the boiler, being theredeflected upward and forward and caused to pass forward through theopenings m to the front of the boiler, where they may be again deflectedand caused finally to pass through the openings to the chimney, or theymay be caused to pass forward through all the openings m and Z and godirectly to the chimney.

It will be noted that as a result of the conconstruction described thesteam is generated in and delivered to the heating system from thatportion of the apparatus which is nearest the hottest part of the fire,while the returning water of condensation instead of directly enteringthe generator and cooling the water therein is brought into a coolerpart of the apparatus, where it is enabled to absorb part of the heatremainingin the waste products of combustion, and it is not delivered tothe generator till it has reached a temperature approximating theboiling-point. Thus I am enabled to utilize most efficiently thegreatest heat of the fire to produce steam of high temperature and tosave much of the heat, which would otherwise be wasted, remaining in theproducts of combustion, thus greatly l increasing the efficiency of myboiler over those heretofore known, in which the cool water is broughtdirectly in contact with the hottest gases, while the steam in the upperpart of the generator is acted on only by gases which have lost a greatproportion of their heat.

The boiler of the form shown in Figs. 3 and 4 is adapted to be usedwithout alteration as a heater for the water of a hot-water heatingsystem, the only difference in operation being that when used ashot-water heater the entire heater is filled with water, no steamspacebeing reserved, and the chamber a' becomes a main water-heating chamberinstead of a steam-generator; otherwise the operation is the same, thehot water flowing out of the outlet o; to the heating system and thecool return water entering the chamber 3 by the inlet CZ and thereoverflowing the wall y to the chamber a.

In Fig. is shown a heater for heating water to be used instead of steamin a heating system, embodying a modified form of the boiler shown inFig. l. The construction and operation of this form of the invention aresubstantially the same as that shown in Fig. l, except that the pipes Aand B are omitted and an external pipe A2, leading from the upperwater-receiving chamber 6 to the heatingchamber a2 substituted therefor.The returning cool water enters through the inlet (Z2, circulatesthrough the chambers 5 and 6, as in the steam-generator, and passesthrough the pipe A2 into the heating-chamber a2, where it is heated tothe required degree instead of being converted into steam, and finallyiiows out by means of the outlet c2 to the heating system.

A great advantage resides in my invention by reason of the fact that asa result of the efliciency with which the heat given off by the fire isutilized and also on account of the comparatively small bulk andshallowness of the body of water contained in the main heating-chambersteam may be generated in the apparatus when used as a boiler or waterheated to the desired degree when used as a water-heater much morequickly and with less expenditure of fuel than with the heaters now inuse. This is particularly desirable in moderate weather, especially whenthe apparatus is used as a steam-boiler, as steam in great economy offuel. With all other boilers a comparatively hot fire is necessary tomake any steam at all, whether in cold or mild weather, and as aconsequence nearly as much fuel must be used to run them when thetemperature is just low enough to make a fire necessary as when it isvery severe.

The arrangement of the inlet and outlet passages to and from thewater-receiving chambers or space, with the former near the bottom whilethe latter is at the top thereof and the outlet-passage from thewater-receivmay be generated from a low fire, resulting ing spaceextending near the bottom of the main heating-chamber, causes the waterto circulate in a natural manner, entering the lowest part of thereceiving-space and there coming into contact with the hot gases passingby this chamber, flowing upward therein as it becomes heated and of lessspecific gravity until it overflows into the outlet-passage, then beingconducted to the lowest part of the heating-chamber, from which it risesin the same manner as it becomes further heated; and as the heater isopen to both ends of a closed'system of pipes the pressure at all pointsin the heater and pipes is substantially the same, so that the returnwater is free to liow naturally back into the heater under the influenceof gravity and without the necessity of external forcing means. By thismeans as soon as a re is started a circulation of water in the heater,and thereby a fiow through the pipes of the system, is set up whichcauses the latter to become warmed in the minimum of time.

o o, Fig. l, represent vent-openings formed in the pipe or passage B,and o', Fig. 3, represents a vent-opening formed in the passage A. Saidvent-openings communicate in each case with the steam-space of the mainheating portion and prevent a siphonic flow of water from the primaryheating portion through either the passages A B, Fig. 1, or the passageA', Fig. 3.

I claim-- l. In a heating system for buildings, a heating apparatuscomprising an outer shell subdivided internally to form a main heatingportion located in close proximity to the source of heat` and havingmeans at its upper part for connection with the supply end of a systemof heating-pipes, a preliminary heating portion located farther from thesource of heat than the main heating portion, and having means at itslower part for connection with the return end of the system, and apassage connecting the upper part of the preliminary heating portionwith the lower part of the main heating portion, whereby the watersupplied by the return-pipe is caused to rise in the preliminary heatingportion, and then to flow through said passage to the lower part of themain heating portion, in which the water again rises.

2. In a heating system for buildings, a heating apparatus comprising anouter shell subdivided internally to form a main heating portion locatedin close proximity to the source of heat, and having means at its upperpart for connection with the supply end of a system of heating-pipes, apreliminary heating portion located farther from the source of heat thanthe main heating portion, and having means at its lower part forconnection with the return end of the system, and a passage connectingthe upper part of the preliminary heating portion with the lower part ofthe main heating` portion, the preliminary heating portion having alsoat its upper part means for connection with the supply end of theheating system, whereby steam or air accumulating in the saidpreliminary heating portion may be liberated.

3. ln a heating system for buildings, a heating apparatus comprising anouter shell subdivided in ternally to form a main heating portionlocated in elose proximity to the source of heat, and having means atits upper part for connection with the supply end of a system ofheating-pipes, a preliminary heating portion located farther from thesource of heat than the main heating portion, and having means at itslower part for Connection with the return end of the system, and apassage Connecting the upper part of the preliminary heatingI portionwith the lower part of the main heating portion, said passage having avent-opening Communicating with the steamspaee of the main heatingportion, whereby a siphonie iiow of water from the preliminary heatingportion to the main heating portion is prevented.

4. In a heating system for buildings, a heat ing apparatus comprising anouter shell having its interior divided into a main heatingspaee and awater-receiving space, the former being' loeated nearer the source ofheat than the latter, a Connection between the upper part of the mainheating-space and one end of the pipe system, a connection between thelower portion of the water-receiving spaee and the return end of thepipe system, and a passage leading 'rom the upper part ot' thewaterreeeiving space to the lower portion of the main heating-space andContained within the shell of the apparatus.

In testimony whereof I have alliXed my signature in presence of twowitnesses.

NVILLIAM S. VSHBURN.

Vllitnesses:

A. H. BROWN, C. F. BROWN.

